Patent Application
20210283533
The invention concerns a liquid filter, in particular an oil filter, for filtering a liquid, in particular an oil, which comprises a raw-side inflow face and a clean-side outflow face, connected to each other by means of a throughflow path, and a filter body comprising a filter medium folded to a folded bellows with a plurality of folds, wherein each fold comprises a fold edge height and two oppositely positioned fold end faces, and wherein the folded bellows is configured to be installed in an installation space that delimits an installation space volume by means of a base free-form surface, a cover free-form surface, and a side free-form surface.
Such liquid filters are known. These are liquid filters that are employed for filtration of liquids. The liquid can be, for example, oil or fuel. In this context, the liquid filter will be installed in a filter assembly that can be used, for example, in internal combustion engines.
For purposes of filtering, the liquid to be filtered (raw liquid) is guided via the throughflow path to the raw-side inflow face of the liquid filter. In the throughflow direction, the filter body is arranged downstream of the raw-side inflow face. It is formed of the folded bellows with the filter medium that is folded such that it comprises a plurality of folds across which the liquid to be filtered is guided. In this context, the folds of the folded bellows each have a fold edge height and two fold end faces that are each arranged perpendicularly to the throughflow direction of the liquid to be filtered. After completed filtering of the liquid (clean liquid), the clean liquid exits then at the clean-side outflow face from the liquid filter. It can then be supplied to its further use.
Such a liquid filter is installed in an installation space through which the liquid (raw liquid) to be filtered is guided. The installation space is typically adapted to the external requirements of those constructive structures in which it is positioned. These structures can be, for example, an internal combustion engine. Depending on the constructive requirements in regard to such installation spaces, their configuration will be very different. In general, it will deviate from simple geometric shapes, such as cuboids or the like. Such an installation space is therefore delimited or defined by means of a base free-form surface, a cover free-form surface, and a side free-form surface. These mentioned surfaces can deviate from simple geometric basic shapes, such as rectangles, triangles or the like. In this context, the folded bellows is arranged on the base free-form surface so that the fold edges extend from the base free-form surface in the direction toward the cover free-form surface. The fold edge height is then the height of the fold edges above the base free-form surface. Moreover, the fold end faces extend parallel to an extension of the side free-form surface from the base free-form surface in the direction toward the cover free-form surface.
The folded bellows of the filter body comprises a folded bellows base surface. This folded bellows base surface is arranged on the base free-form surface. In this context, it is known to embody the folded bellows base surface of a rectangular shape. The dimensions of this rectangular shape are then adapted to the base free-form surface such that the folded bellows in its rectangular shape is accommodated on the base free-form surface. The same holds true for the fold edge heights. They are all adjusted such that they comprise an identical fold edge height across the folded bellows base surface which at most corresponds to a smallest distance from cover free-form surface to base free-form surface in the installation space. In this way, the folded bellows or the liquid filter can be accommodated in the installation space volume.
In this arrangement of the liquid filter, certain installation space sections however remain unused in case of an installation space deviating from a simple geometric basic shape, such as a cuboid, insofar as no filter medium is arranged therein. This results in misshapen liquid filters in the aforementioned installation spaces. They utilize the existing installation space badly and therefore provide only a minimal filtration efficiency.
It is therefore the object of the invention to provide a liquid filter that optimally utilizes an existing installation space volume and therefore provides a high filtration efficiency. Also, an inexpensive manufacture with as few components as possible is to be achieved. Moreover, an advantageous use is to be disclosed.
This object is solved by a liquid filter, in particular oil filter, for filtering a liquid, in particular an oil, comprising a raw-side inflow face and a clean-side outflow face, connected to each other by means of a throughflow path, and a filter body which comprises a filter medium folded to a folded bellows with a plurality of folds and extending between two rim folds, wherein each fold comprises a first fold sheet and a second fold sheet adjoining each other at a fold edge, a fold edge height, and two oppositely positioned fold end faces, and wherein the liquid filter is configured to be installed in an installation space that delimits an installation space volume by means of a base free-form surface, a cover free-form surface, and a side free-form surface, wherein the liquid filter is characterized in that the folded bellows is of a one-piece configuration and at least two of the plurality of folds comprise a different height, wherein the fold edge heights are adapted to an uneven or slanted course of the contour of the cover free-form surface and/or of the base free-form surface, and wherein the fold end faces of at least two folds are adapted to a course of the contour of the side free-form surface facing it, wherein the shape of an envelope of all fold end faces and of the rim folds deviates from a rectangle.
Further embodiments of the invention are disclosed in the dependent claims.
The liquid filter according to the invention comprises a folded bellows of folded filter medium with a plurality of folds. Each fold comprises a first and a second fold sheet which adjoin each other at a fold edge. Neighboring folds of the folded bellows also adjoin each other with their lateral edges at a fold edge. The respective first fold sheets of neighboring folds are positioned substantially parallel to each other. The fold sheets extend between an inflow face and an outflow face. The end faces of the folds extend substantially perpendicularly to the inflow face and outflow face. Within a fold, the fold height is constant, i.e., the fold height of the bellows can change in fold direction but not in the direction along the fold edges. In the liquid filter according to the invention, the folded bellows is of a one-piece configuration and at least two fold edge heights of the plurality of folds are adapted to a course of the contour of the cover free-form surface or the base free-form surface. The extension of the contour of the cover free-form surface is illustrated by the course of a connecting line of a plurality of selected points on the cover free-form surface as a function of the perpendicular distance of corresponding points on the base free-form surface. The same applies to the base free-form surface. The base free-form surface and/or the cover free-form surface is positioned at a slant in this context or is uneven, i.e., it comprises at least one incline, curvature and/or step. When one of the two aforementioned surfaces is flat and the other surface is not, the distance between these two surfaces varies.
The fold edge height of the folded bellows is thus variable within the folded bellows. Different fold edge heights in a one-piece folded bellows can be present. In this way, the fold edge height can be adapted flexibly to the existing installation space. The fold edge height is adapted in this context to the height of the installation space (the perpendicular distance between a point on the base free-form surface and a point on the cover free-form surface). In this way, the existing installation space is covered in its height optimally by the adjustment of the fold edge height to the installation space height. A better filtering efficiency can be achieved, in particular by the possibility of reducing the pressure loss by means of a larger filter surface area. At the same time, the separation efficiency can be increased. In this way, an increased separation efficiency can also be achieved by the use of a filter medium with a higher separation with an unchanged pressure loss in comparison with a liquid filter of a conventional configuration. The larger filter surface area provides also the possibility of prolonging the service life or the service interval of the liquid filter. Also, installation and attachment parts can be integrated better by adaptation of the fold edge height to the conditions of the cover free-form surface or the base free-form surface.
In this context, it is advantageous that the folded bellows comprises at least two folded bellows sections with a different fold edge height that are configured to leave unoccupied a respective predetermined distance from the cover free-form surface section in at least two cover free-form surface sections of the cover free-form surface.
The cover free-form surface can be composed of two or more different cover free-form surface sections. These different cover free-form surface sections can each comprise a height above the base free-form surface that are different from each other. The folded bellows of the liquid filter takes into account these conditions of the installation space by means of the configuration of the folded bellows sections corresponding to the cover free-form surface sections. The fold edge height in each folded bellows section is adapted individually to the available installation space height. This is achieved in that a respective predetermined distance in each folded bellows section between the respective fold edges and the cover free-form surface is left unoccupied. The distance between the fold edges and the cover free-form surface thus follows the shape of the cover free-form surface; in this context, the distance can be constant but also, in accordance with the conditions of the cover free-form surface, can vary also within a cover free-form surface section. The distance, depending on the requirements, for example, the integration of installation or attachment parts, can be varied. The existing installation space volume is optimally utilized. In case that the filter element is installed in a housing with an inflow-side housing cover, the cover preferably emulates the shape of the cover free-form surface. Alternatively, the cover can follow the course of the inflow face.
It is therein preferred that a distance between two neighboring first fold edges in a folded bellows transition section between the two folded bellows sections is different from a distance between two neighboring second fold edges in a folded bellows section.
Accordingly, not only the fold edge height is adapted to the existing installation space but also (additionally) the folding of the filter medium is varied in accordance with the conditions of the installation space. In this way, also edges, steps or the like which are existing in the base free-form surface can be covered optimally with the filter medium. The folds can simply “bridge” such edges or steps by means of the variation of the distance between the individual fold edges.
In the liquid filter according to the invention, at least two fold end faces are alternatively or additionally adapted to a course of the contour of the side free-form surface facing them. The side free-form surface deviates from a standard rectangular shape and can optionally comprise at least one curved side free-form surface section. The contour of the side free-form surface is illustrated by the course of a connecting line of a plurality of selected points on a first side free-form surface as a function of the perpendicular distance of corresponding points on the side free-form surface positioned opposite thereto.
Accordingly, the course of a circumferential contour of the folded bellows can be adapted to the course of the side free-form surface. The fold end faces follow the course of the side free-form surface along its course even when the side free-form surface is curved, i.e., comprises a curved side free-form surface section. In this way, a variable fold length is provided. The contour of the envelopes of all end faces at one side can deviate from the contour of the envelopes of all end faces at the other side. Thus, the folded bellows base surface emulates or reproduces the base free-form surface.
The base free-form surface is optimally utilized and (almost) completely covered by the filter medium. The folded bellows base surface deviates from the conventional rectangular shape and can be adapted flexibly to the existing base free-form surface. A better filtering efficiency can be achieved, in particular by the possibility of reducing the pressure loss by a larger filter surface area. At the same time, the separation efficiency can be increased. In this way, an increased separation efficiency can also be achieved by the use of a filter medium with a higher separation with an unchanged pressure loss in comparison with a liquid filter of a conventional configuration. The larger filter surface area provides also the possibility of prolonging the service life or the service interval of the liquid filter. Also, installation and attachment parts can be better integrated by adaptation of the folded bellows base surface to the conditions of the base free-form surface.
It is advantageous that in addition the at least two fold edge heights of the plurality of folds are adapted to the course of the contour of the cover free-form surface. The course of the contour of the cover free-form surface is illustrated by the course of a connecting line of a plurality of selected points on the cover free-form surface as a function of the perpendicular distance of corresponding points on the base free-form surface.
Also, the fold edge height of the folded bellows is thus variable within the folded bellows. Different fold edge heights may be provided in a one-piece folded bellows. In this way, the fold edge height can be adapted flexibly to the existing installation space. The fold edge height is adapted in this context to the height of the installation space (the perpendicular distance between a point on the base free-form surface and a point on the cover free-form surface). In this way, the existing installation space is covered additionally in its height optimally by the adjustment of the fold edge height to the installation space height. A better filtering efficiency can be achieved, in particular by the possibility of additionally reducing the pressure loss by a larger filter surface area. At the same time, the separation efficiency can be additionally increased. This can be achieved also by the use of a filter medium with a higher separation with unchanged pressure loss in comparison with a liquid filter of a conventional configuration. The larger filter surface area provides also the possibility of prolonging the service life or the service interval of the liquid filter. Also, installation and attachment parts can be additionally integrated optimally by the additional adjustment of the fold edge heights to the conditions of the cover free-form surface.
The folded bellows is preferably introduced into a housing pot with a sidewall and a bottom surface. In order to optimally utilize the installation space, the shape of the sidewall corresponds to the shape of the side free-form surface and the shape of the bottom surface corresponds to the shape of the base free-form surface. The housing pot can remain open or can be closed by a housing cover. The shape of the housing cover is preferably adapted to the shape of the cover free-form surface. In this context, it is advantageous when the housing cover covers a portion of the inflow face as minimal as possible. For this purpose, the cover can comprise a plurality of openings, for example, can be embodied as a grid. The cover can be connected detachably or non-detachably to the housing pot. The folded bellows can be connected with the rim sides and the end faces to the housing pot. A section of the rim folds can be compressed between housing pot and cover.
In all of this, it is preferred that at least one fold at the raw-side inflow face and/or at the clean-side outflow face and/or at least one fold end face is fastened by means of clamping, compressing, gluing or welding to the sidewall of the filter pot, respectively.
In a folded bellows of a one-piece configuration, it is thus possible to dispense with an attachment of the folded bellows in the housing by means of embedding by injection molding. The filter body can be assembled or framed, for example, by glued-on side bands. By means of a joining process (e.g., gluing, welding etc.), the filter element with flexible configuration can then be put together and installed in the housing. When the folded bellows is fastened fixedly in the filter pot, a housing cover can be dispensed with.
Also, it is advantageous that the folded bellows is formed continuously of a single material.
The manufacture of such a one-piece folded bellows is possible inexpensively and efficiently.
The one-piece filter bellows is preferably embodied of a so-called deep filtration filter medium. Suitable such filter media are preferably wet-laid or dry-laid randomly oriented fiber materials which are mechanically and/or chemically reinforced. Such a randomly oriented fiber material comprises hollow spaces between the fibers. The filter medium can comprise natural fibers and at least a proportion of synthetic fibers, for example, polyethylene terephthalate (PET) and/or glass fibers whose proportion can be selected so as to be adapted to the respective filtration application. The proportion can be, for example, a proportion of greater than 10% by weight. The filter medium can also be comprised of synthetic fibers and/or glass fibers wherein, in case of a mixture of synthetic fibers and glass fibers, the mixture ratio can be adaptively selected for the respective filtration application.
The filtration medium can be embodied as a single layer or as multiple layers; for example, a so-called two-substance poured material but also a multi-substance poured material can be selected. In case of a two-substance but also a multi-substance poured material, a fiber slurry of a predetermined fiber type or of a predetermined mixture of fiber types is poured onto a prior formed or still forming nonwoven. The basic laid fiber product may comprise in particular additional layers which can be joined by, for example, material-fusing, in particular thermal, joining methods, for example, by lamination or ultrasonic welding.
Preferably, in case of a two-layer or multi-layer configuration, the clean side layer or the clean side and the raw side layers, in other words one or the respective outer layer, can be formed as a grid structure (drainage grid). This stabilizes the overall configuration additionally and ensures that the fold position in the situation of use remains in position in an optimized manner. The thickness of the filter medium can amount to, for example, between 0.3 mm to 5 mm. The air permeability preferably amounts to between 200 l/m2s to 3,000 l/m2s.
Synthetic or glass fiber media are preferred for so-called lifetime (length of life) applications such as, for example, transmission oil filtration.
Finally, it is preferred that the fold edge height lies in a range between 2 mm to 100 mm, preferably 4 mm to 80 mm, particularly preferred between 8 mm and 50 mm.
Not least, it is preferred that the liquid filter is configured as a suction-side transmission oil filter. In this way, the performance of oil management in a motor can be improved.
Alternatively, the liquid filter according to the invention is employed in a “pressureless” system, i.e., in a system without pump. In this context, the liquid is not forced by pressure or sucked through the filter, but the liquid passes through the filter medium, following the force of gravity. Due to the optimal installation space utilization, the pressure loss across the filter is particularly minimal so that it is suitable particularly well for the pressureless use, i.e., without pump.
The liquid filter according to the invention is used particularly advantageously in an E-axle of a motor vehicle. The E-axle combines motor, transmission, axle, and power electronics in one component and is used in vehicles with electric drive or hybrid drive. The transmission is supplied with transmission oil wherein some components require a defined purity of the oil. The liquid filter according to the invention filters the transmission oil. The unpurified oil is supplied to the inflow face of the liquid filter, trickles through the filter medium to the bottom of the filter pot, and exits the latter through one or a plurality of outlets. The filtered transmission oil is then supplied to the corresponding components.
Further advantages result from the following drawing description. In the drawings, embodiments of the invention are illustrated. The drawings, description, and claims contain numerous features in combination. A person of skill in the art will consider the features expediently also individually and combine them to expedient further combinations.
The Figures show only examples and are not to be understood as limiting.
Moreover, one can see in
In a direction of force of gravity, the liquid filter 1 is limited in its extension toward the top by a housing cover with a cover free-form surface 8. The configuration of this cover free-form surface 8 depends on the installation space that is available in the application. It will therefore in general deviate from simple geometric basic shapes such as rectangles or the like. In the example of
It can be seen in
In
In
In
In this context, it is shown in particular in
As a whole, the available height across the base free-form surface 12 is thus optimally utilized in the existing installation space. The filtering efficiency of the liquid filter 1 is improved. A filter surface area optimized in relation to the installation space is available. An improved separation efficiency can be achieved. The service life or the service interval of the liquid filter 1 can be prolonged.
As a whole, alternatively to or in particular additionally to the optimized utilization of an installation space that is available and alternatively or additionally to the adaptation of the fold edge height across the base free-form surface 12, the folded bellows base surface itself can be adapted also. For this purpose, fold end faces 22, 23, 24 of the folded bellows 2 are adapted to a course of the side free-form surface 13 facing them and in particular to a curved side free-form surface section 14. This principle is illustrated in
In this context,
In
In this context, it can be in particular seen, respectively, that the folded bellows 2 with its folded bellows base surface completely and optimally fills out the base free-form surface 12, respectively. In this context, the fold end faces 22, 23, 24 are fastened respectively across the circumferential course of the contour of the base free-form surface 12 to the side free-form surface 13 or the curved side free-form surface section 14. This attachment can be realized by clamping, compressing, gluing, welding or embedding by injection molding the fold end faces 22, 23, 24 at the side free-form surface 13 or the curved side free-form surface section 14. Also, the folded bellows 2 can be assembled or framed by glued-on side bands. By a joining process (e.g., gluing, welding etc.), the folded bellows 2 with flexible configuration can then be introduced into a housing pot with sidewalls corresponding to the side free-form surface and installed in the installation space that is available.
As a whole, the available base free-form surface 12 in the existing installation space is optimally utilized by means of the folded bellows base surface. The filtering efficiency of the liquid filter 1 is improved. The pressure loss is minimized. A larger filter surface area is available. A better separation efficiency can be achieved. The service life or the service interval of the liquid filter 1 can be prolonged.
Finally, a section illustration of the
In
The illustrated filter housing with rectangular shape is to be understood as a principal illustration for a housing for a folded bellows for use without pump. Corresponding to the existing installation space, the sidewalls, the bottom surface, and/or the cover will have a contour or shape that is correspondingly adapted.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 130 552.4 | Nov 2018 | DE | national |
This application is a continuation application of international application No. PCT/EP2019/083048 having an international filing date of 29 Nov. 2019 and designating the United States, the international application claiming a priority date of 30 Nov. 2018 based on prior filed German patent application No. 10 2018 130 552.4, the entire contents of the aforesaid international application and the aforesaid German patent application being incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2019/083048 | Nov 2019 | US |
| Child | 17334777 | US |
